To improve safety of our roads a number of safety systems for automobiles have been developed, which entail a variety of differing approaches to the challenge. Many safety systems are concerned with the avoidance of collisions between vehicles and obstacles, pedestrians or other vehicles. Some of these approaches contemplate the use of camera-based vision systems. Notably, camera systems directed forwardly have been employed in an attempt to create self-guiding automobiles and other vehicles. A compendium of various approaches which may employ vision systems is described in Vehicle Surround Capture: Survey of Techniques and a Novel Omni Video Based Approach for Dynamic Panoramic Surround Maps, 2006, some of which should not be considered prior art as not predating applicant's invention of the concepts herein.
Trucks and tractor trailers are responsible for transporting a substantial portion of the goods used in commerce in the US and other countries. They are present on virtually every road or highway. Unlike their smaller counterparts, automobiles and motorized cycles, the size and weight of a truck makes it more difficult to maneuver and stop, and its driver's ability to view obstacles and vehicles (particularly those located behind and aside) may be much more limited. Moreover, when a truck collides with another vehicle or pedestrian, the other smaller vehicle or pedestrian may not survive. Thus, safety systems that warn of the potential for such collisions are highly desirable.
Some trucks are equipped with localized radar units, or other types of sensors, in an attempt to provide warning prior to lane change or turning in an effort to avoid a catastrophic collision. These systems tend to be short range and, in part due to their expense, are mounted only on the cab. Thus, objects/vehicles moving along the side of the rear-mounted truck trailer may not be sensed in time, if at all. Also, stationary objects are not effectively sensed by radar.
Camera-based vision systems offer a potential solution. However, most camera systems tend to view a wide field and a single camera may have trouble discriminating range and movement of an object, in the same way that closing one eye tends to reduce a person's depth perception. While some vehicle guidance systems (mounted front-facing) have employed so-called “stereo vision,” which emulates an animal's natural horizontal placement of eyes so as to provide range discrimination, this approach is not as effective for dealing with objects that tend to have more vertical than horizontal features, such as pedestrians, sign posts and motorcycles. Such objects tend to get lost in the horizontal spread of a conventional stereo vision arrangement.
Accordingly, it is desirable to provide a safety system, employing a camera-based vision system that allows the entire unit to be mounted on the cab so that trailers and cargo structures are removable from the truck without need of changing over any vision system components. The system should allow for the use of conventional camera components with high reliability and durability, should be relatively unobtrusive and provide good discrimination of vertically featured objects along the rearward sides of the truck, behind the cab.